How are smears of cerebrospinal fluid (CSF) prepared for analysis?

Centrifuged CSF sediment is the most appropriate method for preparing smears for analysis because it allows for the concentration of cells and any microorganisms present in the cerebrospinal fluid. By centrifuging the CSF, the cells settle to the bottom, resulting in a sediment that can be readily examined microscopically. This sediment contains a higher concentration of the analytes of interest, including potential pathogens or abnormal cells, making it more suitable for diagnostic purposes.

In contrast, directly pipetting from the CSF container does not concentrate the cells and may lead to a diluted sample that could miss important findings. Using fresh CSF without centrifugation also fails to provide the necessary concentration of cells for effective analysis. Additionally, diluting CSF with saline may further reduce the concentration of cells and other components, making it less effective for detecting infections or abnormalities. Therefore, preparing smears from centrifuged CSF sediment enhances the likelihood of identifying critical diagnostic information in the analysis.